JohnDoe Hi, the Pixel 3a is end of life so it no longer receives security patches which defeats the purpose of running GrapheneOS.
For example, you lose protection against zero day vulnerabilities: https://grapheneos.org/features#exploit-protection
GrapheneOS can't support older devices once the
firmware, kernel and vendor code is no longer actively maintained. Here's why:
https://grapheneos.org/faq#legacy-devices